In some cases it is convenient or necessary to use a fluid warmer to heat a continuously-flowing fluid to a target temperature or range of temperatures, for example to warm intravenous (IV) fluids to body temperature before delivery to a patient.
In a conventional device the fluid flows through an appropriate conduit, and a conductive heater element transfers heat to the fluid through intervening layers such as the conduit walls. In some cases, such as in the IV fluid warmer mentioned above, the conduit is releasably attachable, and may for example be a disposable cassette which is inserted into the fluid warmer unit prior to use.
US 2011/0098642, the contents of which are hereby incorporated by reference, concerns one such fluid warmer. In this device, the IV fluid passes through a disposable ‘set’ which is held in place by slideable covers. When the covers are closed, they apply pressure to the set to compress it towards a heater assembly, creating better thermal contact between the assembly and the set. The size and unevenness of the applied pressure can cause relatively high stresses and deformation of the heater assembly and other elements of the fluid warmer device, reducing efficiency and the lifetime of the device.
The present invention seeks to address these and other problems in the prior art.